1. Field of the Invention
The present invention relates to a crane.
2. Description of Related Art
A crane is provided with rear post support members (for example, cables) that support a rear post in a crane task (cargo-handling task). Japanese Laid-Open Patent Publication No. H8-48489 describes a method of mounting rear post support cables, in which a hydraulic cylinder is interposed between a rear post and a boom of a crane in such a manner that the rear post is rotatable, and rear post support cables that has been divided in two are connected to each other and are installed in the crane.
In the method described in the aforementioned publication, the rear post and a front post are attached to a boom head of a tower boom that has been rotated to lie down in a horizontal position. One end of one rear post support cable is engaged to a tip end of the rear post, while one end of the other rear post support cable is engaged to a cable mounting part of the tower boom. The other rear post support cable is laid on the tower boom so that the other end of this cable is arranged on the rear post side.
When the hydraulic cylinder is retracted, the rear post is rotated down to the tower boom side, so that two rear post support cables are coupled to each other. Thereafter, the hydraulic cylinder is extended so that the rear post raises up at a predetermined angle and the rear post support cables are installed.